The present invention relates to a spray apparatus for coating materials, in particular for coating powders.
In particular the present invention relates to a spray apparatus comprising at least one high-voltage electrode electrostatically charging the coating material. However it also applies to spray apparatus which are not designed to electrostatically charge coating materials.
Spray apparatus of this kind are known for instance from the patent documents U.S. Pat. No. 4,324,361; DE 34 12 694 A1; U.S. Pat. Nos. 4,505,430; 4,196,465; 4,347,984 and 6,189,804.
Spray apparatus fitted with shaping-air outlets of annular gap geometry incur the drawback that if said gap is supported along its longitudinal direction at several places, manufacturing constraints will preclude uniform gap size. Such a drawback however is averted by using boreholes instead of an angular gap, especially if the body containing said boreholes remains undivided at the borehole site. Illustratively such spray apparatus are shown in the patent documents EP 0 767 005 B1; EP 0 744 998 B1 and DE 34 31 785 C2.